London farms fish and greens

LONDON — Inside a warehouse in industrial southeast London, farmed tilapia swim in blue tubs filled with pristine water, ready to be sold to trendy restaurants across the capital.

In an adjacent room, under pink LED lights and controlled temperatures, shoots of salad leaves and herbs grow on recycled carpet fiber fertilized with the fish waste. In this cavernous, windowless space more suited to a nightclub than a farm, the greens are stacked on metal shelves stretching to the ceiling.

It’s a far cry from traditional British farms that sprawl across acres of land. But for Kate Hofman, who co-founded GrowUp Urban Farms in 2013, producing food in this 557-square-meter building in Beckton was not only clever and cost-effective. It was also a sustainable way to feed people in the city.

“Sometimes people have an idealized idea of how their food is being produced. In their head, they think that farmer Joe tends to his field with his hoe and grows his heads of lettuce,” the 32-yearold says.

“We’re trying to show that you can have an industrialized food system ... but you can do it in a way that’s sustainable,” says Hofman, who launched Britain’s first commercial aquaponic farm — a system that uses fish waste to fertilize crops, which in turn filter the water used to farm the fish.

Rich and poor countries alike are tasked with creating sustainable and inclusive cities by 2030 under global development goals agreed in 2015 — and sorting out how cities are fed is a crucial part of that challenge, experts say.

As two-thirds of the global population are forecast to live in cities by 2050, compared with about half now, urban planners and policymakers are increasingly looking to agriculture in towns and cities as a solution to provide nutritious food.